EP 1070526 A2 2001-01-24 - Foam control agents

Title (en)

Title (de)

Title (fr)

Publication

Application

Priority

GB 9917331 A 19990723

Abstract (en)

A foam control agent comprises a homogeneous mixture of an organopolysiloxane (A) and a stabilising aid (B) containig a finely divided hydrophobic filler (C ) at 0.1 to 15% by weight. The siloxane units of (A) consist essentially of 0 to 60% of units of the general formula (i) RaSiO(4-a/2) wherein R denotes a hydrocarbon group having up to 8 carbon atoms and a has a value of from 0 to 3, and 40 to 100% of units of the general formula (ii) RbR''cSiO(4-b-c/2) wherein R'' denotes a group -Zz-R', wherein R' denotes an alkyl group having from 9 to 35 carbon atoms, Z denotes a linking group between silicon and R' and z has a value of 0 or 1, b has a value of 0, 1 or 2, c has a value of 1 or 2, and b+c has a value of 1, 2 or 3, provided more than 70% by weight of the carbon content of the organopolysiloxane is due to the groups R''. (B) has a melting point of 40 to 80 DEG C and preferably is a fatty acid, a fatty alcohol, and an alkylphosphoric acid of the formula:- <CHEM> wherein R<j> is a linear or branched alkyl or alkenyl group containing from 12 to 24 carbon atoms EO represents ethylene oxide and s is zero, 1 or 2. (B) in its liquid form is preferably miscible with the organopolysiloxane (A) so as to form a homogeneous liquid which upon cooling forms a monophasic waxy substance.